1. Field of the Invention
The present invention relates to a method of fitting a throttle cable for interconnecting a throttle valve operating cam of an automatic transmission and a throttle valve of an automotive vehicle engine, and a structure for fitting the throttle cable to the automotive vehicle engine.
2. Description of Related Art
An automatic transmission for an automotive vehicle is typically provided with a throttle valve (which is hereinafter referred to as a transmission throttle valve) cooperating with a throttle valve of an engine (which is hereinafter referred to as an engine throttle valve). The automatic transmission requires a locking force for locking a transmission clutch which depends upon an engine output. If a high locking force is applied to the clutch, even though an engine output is low, a great shock is produced when the automatic transmission is shifted. To avoid such transmission shocks, it is preferred to make the difference between openings of the transmission throttle valve and the engine throttle valve is as small as possible.
In an attempt at avoiding such a transmission shock, an accelerator pedal and a throttle lever have been interconnected by means of a cable, and the throttle lever is connected to a throttle cam by another cable. These cables are arranged and fitted to the engine and automatic transmission. Such a cable arrangement is known from Japanese Unexamined Patent Publication No. 55(1980)-30,534.
To interconnect the throttle cam and the engine throttle lever by an inner cable extending through the inside of outer cable tube, after fitting a marking member to an inner cable near one end, opposite to the other end which has been connected to the throttle cam of the automatic transmission, the transmission throttle cam is turned by back-and-forth strokes between its two extremes, namely its fully closed and fully opened positions to measure distances between the marking member and a cable fitting bracket secured to the automotive engine. After coupling the automatic transmission to the automobile engine, the throttle cable is connected to the engine throttle lever at the other end in such a way that distances between the marking member and the cable fitting bracket agree with the measured distances when the engine throttle lever is operated so as to turn the transmission throttle cam between the fully closed and full open positions.
In the conventional arrangement, because the determination of the proper tension of the throttle cable is made by measuring the distance of the marking member from the cable fitting bracket, the actual tension applied to the throttle cable depends on the accuracy of measurement. Moreover, because the automotive vehicle engine and the automatic transmission have many parts attached thereto around locations where the throttle cable is fitted, it is, practically, difficult to measure the distance with a high accuracy. Additionally, because the arrangement of the throttle cable depends on not only the types of automotive vehicle engines but also on the automotive vehicle engines themselves, even when they are of the same type, it is necessary to provide various lengths of inner cables and outer cable tubes.